1. Technical Field
The present application relates to a lithium secondary battery.
2. Description of the Related Art
For use in electric vehicles and for electric storage purposes, secondary batteries are expected to increase in size, especially in order to produce high output power. Generally speaking, a secondary battery is structured so as to include a positive electrode and a negative electrode, and an ion conductor interposed therebetween. As ions migrate between the positive electrode and the negative electrode with oxidation/reduction of the positive electrode and the negative electrode, the secondary battery is able to undergo charging and discharging.
In order to obtain high output power, it is important to reduce the resistance against migration of ions as a carrier. Japanese Patent No. 3971911 (hereinafter, referred to as Patent Document 1) discloses a problem that, in a secondary battery containing lithium cobaltate as a positive-electrode active material, when the lithium cobaltate is made into a thin layer, a layer which is oriented in the c axis direction is likely to be formed, thus hindering smooth exchange of ions. Therefore, Patent Document 1 proposes using as an active material layer a layer whose c axis is inclined by 60° from the principal face.